Activation mechanism of host-defense molecule in fish blood

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K15319
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Aquatic life science
• Research Institution: Kanazawa University
• Principal Investigator: Kitani Yoichiro 金沢大学, 環日本海域環境研究センター, 助教 (70565340)
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: L-アミノ酸オキシダーゼ / 魚類 / 生体防御 / 抗菌タンパク質

Outline of Final Research Achievements

We found a novel L-amino acid oxidase from Orange-spotted grouper serum. This LAO was existed as an inactivated form in the blood of the grouper, because of the toxicity of hydrogen peroxide that provides by L-amino acid oxidation. The activation mechanisms of grouper LAO were investigated and ions that contain seawater such as sodium, potassium and calcium were triggered to activate. Activating concentration of those ions was almost the same as seawater contents. Those results suggested that the grouper LAO was typically inactive form and was activated by contact with seawater.

Free Research Field

水産化学

Academic Significance and Societal Importance of the Research Achievements

本研究により、強力なラジカルジェネレーターであるLーアミノ酸オキシダーゼが生体内で不活性体として存在し、必要に応じて活性化しその機能を示すことが明らかとなった。これはLAOが感染症等からの生体防御の際に厳密に制御された攻撃手段として存在することが予想される。この成果は魚類のみならず他の生物におけるLAOを中心とした生体防御機構の理解へ向けた端緒となる。